What is this test?
This laboratory test is performed on a blood sample to measure the levels of unconjugated bilirubin. Bilirubin is a pigment made from the breakdown of red blood cells and is excreted into the blood by the liver. Unconjugated bilirubin is normally found in the plasma, it is the fraction of bilirubin not conjugated in the liver while conjugated bilirubin is the fraction of bilirubin conjugated with glucuronic acid in the liver.
Why is this test performed?
This test is performed:
- To help in the diagnosis of a transfusion reaction
- To help in the diagnosis of sickle cell or hemolytic anemia
- To help in the diagnosis of bile duct obstruction
- To help in the diagnosis of a suspected Crigler-Majjar syndrome
- To help in the diagnosis of a suspected Gilbert syndrome
- To help in the diagnosis of physiological and neonatal jaundice
- To help in the diagnosis of Hepatitis and cirrhosis.
- What will affect my test results?
- Exercise
- Barbiturates
- Penicillin
- Salicylates
- Atzanavir
- What are the risks of this test?
Collecting blood from a vein is a very easy procedure and pose only minimum risk, including:
- Bruising
- Bleeding
- Infection
- How to prepare for the test?
Do not eat or drink anything except water 4 hours prior to the test. Inform your doctor about the use of all prescribed and non-prescribed medicines. Wear a short-sleeved shirt to aid the collection of sample.
- What other tests might be ordered by my doctor?
- Alkaline phosphatase
- Albumin
- Prothrombin time
- LDH
- Aspartate
- Alanine
- CBC
- Why unconjugated bilirubin levels increase in hemolytic anemia?
Unconjugated bilirubin levels increase in hemolytic anemia as a result of large amounts of RBC destruction which exceeds the capacity of liver to conjugate bilirubin.
Normal range: 0.2-0.8 mg/dL
Interpretation of test results:
Causes of increased Unconjugated bilirubin levels:
- Transfusion reaction
- Sickle cell anemia
- Hemolytic anemia
- Bile duct obstruction
- Physiological jaundice
- Neonatal jaundice
- Erythroblastosis foetalis
- Hepatitis
- Cirrhosis
- Bleeding into the skin
- Bleeding in the lung caused by a blood clot.